Rotary engine.



J. A. ULBERG. ROTARY ENGINE.

APPLICATION FILED JUNE 3.1918.

1,238,764. Patented Dec. 24, 1918.

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J. A. ULBERG.

ROTARY ENGINE,

- APPLICATION man ms 3. I918- Patented Dec. 24, 1918.

J. A. ULBERG.

ROTARY ENGINE.

APPLICATION nLE01uM3.-191s.-

Patented, Dec. 24, 1918.

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JOHN A. ULBERG, OF MOTT, NORTH DAKOTA.

- ROTARY ENGINE;

Application filed June 3. 1918.

To all whom it may concern:

Be it known that I, JOHN A. ULBERG, a citizen of the United States, residing at Mott, in the county of Hettinger and State of North Dakota, have invented certaln new and useful Improvements in Rotary Engines, of which the following is a specification.

My invention relates to that type of rotary engines in which the piston head runsin an annular working chamber in the engine casing and is mounted on and carried by a disk fitted within the casing and keyed upon an engine shaft rotatably mounted in said casing, as shown for example in my Letters Patent No. 1,248,208 of Nov. 27, 1917; and my invention consists in certain improvements in rotary engines of this type, which will first be described in connection with the accompanying drawings forming a part of this specification and will then be more par ticularly pointed out in the claims.

In the drawings,

Figure 1 is a front elevation of a rotary engine embodying my improvements in their preferred form,

Fig. 2 is a side elevation partly broken away of the engine casing with the plping and other extraneous fittings removed,

Fig. 3 is asection on enlarged scale on line 33 Fig. 2, the right-hand swing abutment being removed,

Fig. 4 is a section on enlarged scale on line 4-4 of Fig. 2,

Fig. 5 is a side elevation of theinner face of one of the halves of the casing, with the piston disk fitted thereina portion of the disk being broken away to show. the swing abutment mounted in that half of the casing, the recess formed in said half to accommodate the abutment, and the ports in the recess through which the steam enters the working chamber back of the abutment when the latter is, folded back into said recess as in the engine of my Patent No. 1, 248,208. The other half of the casing is precisely the same in structure as the half shown in this figure. v

The engine casing consists of two symmetrical halves a, between which, at or near their outer edges a suitable packing (not shown) is interposed, the two halves of the casing being drawn together bybolts, and

' provided" with the usual or. suitable axial Specification of Letters Patent.

Patented Dec. 24, 1918.

Serial No. 237,920.

or secured to the disk r and has a cross section corresponding to that of the working chamber in which it is fitted and adapted to move. The piston head is of course suitably packed to make a steam tight oint with the walls of the working chamber.

In a suitable portion of the piston disk T which doesnot enter the annular working chamber cin the present instance in the hub of the disk-is formed a segmental slot Z extending through. the hub from side to side and part way around the same in a circular path concentric with the axis of revolution of the disk. This slot forms in effect a chamber which is closed on opposite sides by the walls of the two halves of the casing. In each half of the casing and in a path registering with the curve of the segmental slot Z in the disk, is a port it communicating with a steam supply pipe I-I (Fig. l), and an outlet port it which leads through a suitable duct if, [t (Figs. 2, 4.) to the working chamber into which it discharges through one or more ports-in this instance three ports 0 (Figs. 5) located in the recess 5 formed in that side of the working chamber to receive the swing abutment Z) mounted in that half of the casing. The inlet port it is located in advance of the outlet port 7L relatively to the direction of rotation of the piston disk; and the length of the chamber Z determines the cut-off, steam from the chamber Z being admitted to the outlet port h and thence to the working chamber as soon as the outlet and inlet ports meet the chamber Z, and being cut oif when the chamber passes beyond the said outlet port; andthe inlet port it being the last to be cut-off from said chamber, so that during the operation of the engine there is always steam under pressure in the chamber Zafter the steam eduction ports are shut and-until they are again open. The purpose and effect of this arrangement will be hereinafter explained. As before said, there are two ments 6, one in each recess, pivoted therein on pintles I), and two sets of steam inlets cone in each recessdirectly opposite one another at the point where they open into the working chamber, the arrangement and mode of operation of these parts being substantially the same as in my aforesaid patent.'

'At a suitable distance in rear of the swinging abutments Z) exhaust openings 42 (Figs. 1, 5) communicating with the working chamber are located in the walls of the casing. Inasmuch as the piston head is (the front of which is suitably tapered as shown more plainly in the sectional view Fi l to facilitate its passage between the a utments) has some distance to travel, after closing the exhaust a, before reaching the swinging abutments with consequent compression of the fluid contents of the space intervening between the advancing head of the piston and the closed abutments, in order to relieve thatpressure until just before the piston reaches the abutments I form in the piston disk at a suitable distance in advance of the piston, and of proper length, a slot d (Fig. 5) curved concentrically with the axis of revolution of the piston disk. lVhen the piston disk is in revolution, by the time the piston has passed the exhaust n, the portion of the disk in which the slot cl is located will have commenced to pass between the still closed abutmentsb, thus affording a passage way by which the pressure on the opposite faces of the abutments may be equalized, this condition of affairs continuing until the heel of the slot passes beyond the abutments, which will take place at a sufficient interval before the piston reaches the abutments to allow the compression pressure to be increased sufficiently to. fold back the abutments and permit the unimpeded passage of the piston. By the time the piston has passed beyond the abutments thefront end of the steam chamber Z will have come opposite the outlet ports h,'thus permitting the charge of steam under pressure confined therein, to pass through these ports to the inlets 0, back of the now folded back abutments Z) in the working chamber and to act on those. abutments with sufiicient force to swing them gently inwardly toward each other back to their closed position. By the time the abutments have been thus moved, the steam chamber Z in the hub of the disk will have met the steam supply And there are I ports it, thus admitting live steam under full pressure into the working chamber'between the closed abutments and the piston. -In this way the opening and closing movements of the abutments can be effected by fluid pressure gently and without shock.

Apertures m (Fig. 5) in the piston disk are provided to equalize the pressure on both sides of the disk.

.In the casing, is an annular chamber 0; located in that portion ofthe casing between" the'working chamber and the periphery of the casing and preferably formed as indicated in Fig. 3, by matching or registering annular-recesses in the meeting faces of the two halves of the casing. The chamber, whichhas suitable valve or cock-controlled discharge or exhaust pipes w and a pipe 00 connecting with a source of heat supply, is provided for the purpose of heating the casing before starting up the engine, as is sometimes convenient or desirable, in cold weather for example.

In the particular structural arrangement of parts shown in the drawing, steam from the segmentalchamber Z in the hub of the piston disk is led through the outlet porth and duct 72 in the casing to a communieating duct it formed in the underside of the cap h removably secured to the side of the casing, whence it passes through inlets c to the interior of the working chamber. The bearing for the pintle of the swing abutment is formed partly in the inner face of the cap which is removable to permit of convenient access to the abutment whenever necessary or desired.

It is manifest that a single steam supply port'h opening into the steam chamber in the hub of the disk may be used to supply steam to the outlets ports h in the casing on each side of said chamber, and I desire to be understood as including any such obvious modification in my claims. I prefer however the steam supply arrangement shown in the drawings.

Having described my invention and the best way now known to me of carrying the same into practical efiect I state in conclusion that I do not limit myselfstrictly to the structural details hereinbefore shown and described in illustration of the improvements subject of my claims since manifestly the same can be varied considerably without departure from the spirit of my invention;

but what I claim'as of my own'invention and desire to secure by Letters Patent is as follows:

1. The combination with the piston disk and its shaft, the two-part casing provided with bearings for thefshaftr and with re- I cesses in its meeting faces to accommodate the piston and an annular working chamber for the piston head on said disk,'and swing abutments in. opposite sides ofsaid chamber,

of the following elements namely: a segmen tal steam chamber concentric with the axis of rotation of the piston disk formed in a portion of the disk exterior to the working chamber, extending through the piston disk from one side to the other thereof, and closed on opposite sides by the walls of the casing between which the disk revolves; a steam supply port located in a part of the casing where it will meet the segmental steam chamber at appropriate times during the rotary movement of the disk; a steam eduction port in that portion of each of the opposite faces of the casing by which the segmental steam chamber is closed, located therein in rear of the steam supply port, relatively to the direction of rotation of the disk; and ducts leading from the said steam eduction ports to inlets in the Working chamber in advance of the swing abutments therein.

2. In combination with the elements of the combination specified in claim 1, a slot in that portion of the piston disk in the working chamber in advance of the piston head relatively to the direction of revolution of the disk, and located with reference to the piston-head, the swing abutment-s and the exhaust so that it shall enter between the closed abutments after the piston-head has passed beyond the exhaust, for the purpose of equalizing the pressure in front and behind the abutments, and shall pass beyond said abutments before the piston-head reaches the latter.

3. In a rotary steam engine of the type specified, the combination with the piston disk and piston head thereon, the casing having a, working chamber to receive the same. swing abutments in said Working chamber and means for supplying steam to and exhausting it from the working chamber, of an equalizing pressure slot formed in the piston disk in advance of the pistonhead relatively to the direction of rotation of the disk, so that it will enter between the closed abutments, and thus open up communication between the portions of the working chamber in front and in rear of the abutments, after the piston-head has passed beyond the exhaust and will pass beyond the abutment-s and thus discontinue the previously established communication between the portions of the working chamber in front and in rear of the abutments before the piston-head reaches the same, substantially as and for the purpose hereinbefore set forth.

4. In a rotary engine of the type specified the combination with the piston disk and piston head thereon, the two part-casing provided in its meeting faces with recesses to accommodate the piston disk and to form a working chamber for the piston head, and means for supplying steam to and exhausting it from said working chamber, of an annular heating chamber in the meeting faces of said two-part casing, external to and surrounding the working chamber, but having no communication therewith, and means for supplying steam to and withdrawing it from the said heating chamber at will.

In testimony whereof I affix my signature.

JOHN A. ULBERG.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. 0. 

